14 Apr (NucNet): French electric utility EDF and nuclear equipment manufacturer Areva have recommended to the French nuclear safety authority ASN (Autorité de Sûreté Nucléaire) to extend the testing programme for the 1,600-megawatt Flamanville-3 EPR pressure vessel (RPV) until the end of 2016, the two companies said in separate statements.
In April 2015, ASN, Areva and EDF revealed that tests had shown higher than expected carbon segregation in RPV material samples, indicating a possible manufacturing flaw and potentially affecting the vessel’s ability to withstand the propagation of cracks.
The tests followed earlier chemical and mechanical examinations on forged steel parts representative of the RPV, which showed the carbon segregation phenomenon was higher than expected in a certain area.
According to Areva and EDF, analyses showed that the carbon anomaly extended beyond mid-thickness in one of the two steel parts under examination – representative of the RPV head and bottom – which required material sampling and related tests to be extended to three-fourths of the thickness of the part concerned.
The suggested testing programme extension will therefore include examinations of a third forged steel part with the goal to “strengthen the robustness of the demonstration” of the EPR, EDF and Areva said.
The companies said the proposed additional tests will examine 1,200 material samples, a two-fold increase in comparison with previous analyses.
ASN has approved this addition to the testing programme, aiming to guarantee the representative nature of all the RPV parts tested, Areva and EDF said.
The EDF board gave the go-ahead for construction of Flamanville-3 in May 2006, saying it expected to complete the unit by 2012.
In November 2011, the company announced the unit would begin commercial operation in 2016, four years later than originally scheduled. That delay was linked to both structural and economic reasons, EDF said at the time.
In the first quarter of 2015, EDF submitted its commissioning application file to ASN.
In September 2015, EDF said following an assessment of “all the industrial and financial parameters” project costs have been revised to €10.5bn ($11.7bn). An estimate released in July 2011 was €8bn.
In March 2016, EDF reported that the installation and assembly of large components – four steam generators, the RPV, the pressuriser and primary pumps – has been completed at Flamanville-3.
According to the latest statements by Areva and EDF, Flamanville-3 is now expected to become operational in the last quarter of 2018.
Jean-Bernard Lévy, EDF chairman and managing director, said in September 2015 that Flamanville-3 was a priority for EDF and of “critical importance” for the French nuclear industry and its international success. “All of the experience gained at Flamanville will be invaluable for other EPR projects, such as Hinkley Point [in the UK].”
